PURPOSE: To provide an optical position detection device which is simple in constitution, inexpensive, and compact and has a wide angle of field, and an optical coordinate input device which utilizes the optical position detection device.

CONSTITUTION: The optical position detection device is equipped with one image pickup means 23, a pattern member 21 which has a specific pattern arranged in front of the image pickup means 23 on a path of light, and signal processing means 25, 26, 27, and 28 which extract information regarding the distance between a light emission source 3 and the image pickup means on the basis of a detection signal regarding the specific pattern projected in the image pickup area of the image pickup means. To extract the information regarding the distance, the distance between the pattern member and the image pickup area of the image pickup means needs to be known in advance. And, the distance to the light source which emits the light can be found by utilizing one image pickup means. The specific pattern is a pattern which has equal periodicity. The signal processing means perform statistical processing by utilizing the equal periodicity to find an enlargement rate determined by the shadow of the projected specific pattern, and this enlargement rate is utilized to extract information regarding the distance.